The pilot scheme will last for a year from August 2009
Up to 1,000 pupils in Glasgow are to be kept in school at lunchtime in a bid to promote healthy eating.
The city council has agreed a trial scheme involving first year pupils at eight secondary schools.
From August 2009, pupils will have to bring their own packed lunch, buy food from the school canteen or return home.
If the scheme is deemed a success when it ends in 2010 it could be rolled out to more schools across the city and involve other year groups.
Consultation has already taken place with headteachers, staff and young people at St Paul's High, Castlemilk High, Govan High, Whitehill Secondary, St Mungo's Academy, All Saints Secondary, Lochend Community High and St Thomas Aquinas Secondary.
The council intends to enter further talks with parent councils, trade unions and pupils before going ahead with the project.
Glasgow City Council's executive member for education, Bailie Gordon Matheson, said many schools had at least 20 fast food shops within a half mile radius of their gates.
"There is little point in offering cheap and healthy lunches if thousands of our pupils instead buy chips or instant noodles from the local shops.
"Research indicates that healthy food in schools can have a positive influence on children's and parents' dietary habits.
"Children with a nutritionally balanced diet find it easier to concentrate in the classroom and their behaviour tends to be better than that of their peers.
"This initiative could have far-reaching consequences not just for the young people at school, but also for their families and their futures."